US10845460B2 - Sound source position detection device, sound source position detection method, sound source position detection program, and recording medium - Google Patents

Sound source position detection device, sound source position detection method, sound source position detection program, and recording medium Download PDF

Info

Publication number
US10845460B2
US10845460B2 US15/577,569 US201615577569A US10845460B2 US 10845460 B2 US10845460 B2 US 10845460B2 US 201615577569 A US201615577569 A US 201615577569A US 10845460 B2 US10845460 B2 US 10845460B2
Authority
US
United States
Prior art keywords
sound source
measured
signal
reference signals
correction value
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active, expires
Application number
US15/577,569
Other languages
English (en)
Other versions
US20180164403A1 (en
Inventor
Hirofumi Inoue
Naofumi Suzuki
Junichiro Mataga
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NEC Corp filed Critical NEC Corp
Assigned to NEC CORPORATION reassignment NEC CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: INOUE, HIROFUMI, MATAGA, JUNICHIRO, SUZUKI, NAOFUMI
Publication of US20180164403A1 publication Critical patent/US20180164403A1/en
Application granted granted Critical
Publication of US10845460B2 publication Critical patent/US10845460B2/en
Active legal-status Critical Current
Adjusted expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/18—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using ultrasonic, sonic, or infrasonic waves
    • G01S5/22—Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S3/00—Direction-finders for determining the direction from which infrasonic, sonic, ultrasonic, or electromagnetic waves, or particle emission, not having a directional significance, are being received
    • G01S3/80—Direction-finders for determining the direction from which infrasonic, sonic, ultrasonic, or electromagnetic waves, or particle emission, not having a directional significance, are being received using ultrasonic, sonic or infrasonic waves
    • G01S3/802—Systems for determining direction or deviation from predetermined direction
    • G01S3/808—Systems for determining direction or deviation from predetermined direction using transducers spaced apart and measuring phase or time difference between signals therefrom, i.e. path-difference systems
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/18—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using ultrasonic, sonic, or infrasonic waves
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/18—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using ultrasonic, sonic, or infrasonic waves
    • G01S5/20—Position of source determined by a plurality of spaced direction-finders

Definitions

  • the present invention relates to a sound source position detection device and the like, for example, to those which detect a position of a sound source on the basis of a sound signal output from the sound source.
  • Patent Literature 1 discloses a leakage search apparatus for water pipeline which includes two leakage sound detectors, a master device (sound recording and correlation calculation device) and a slave device (leakage sound recording device).
  • the two leakage sound detectors each detect a leakage sound.
  • the master device records a leakage sound signal, analyzes it and displays the output.
  • the slave device is configured to be attachable and detachable to the master device, and records a leakage sound signal.
  • the master and slave devices are each provided with a synchronization circuit, and they are placed at respective measurement sites separated from each other.
  • the master and slave devices are set to record data for the same time period since the same time.
  • an error in data record time between the two devices is calculated by comparing a difference in record time of a broadcast reception signal (obtained by an FM (Frequency Modulation) broadcast receiver) recorded along with sound pressure data. It thereby becomes possible to check that the recording of sound pressure data was started simultaneously in the master and slave devices. Then, sampling points of the sound pressure data are shifted in a manner to cancel out the error in data record time between the two devices. As a result, it becomes possible to achieve synchronization of the recorded sound pressure data.
  • a radio broadcast receiver (FM broadcast receiver) is provided in each of measurement devices (master and slave devices) placed at respective sites separated from each other and, taking their broadcast reception signals as reference signals, synchronization of sound pressure data is performed.
  • Patent Literature 2 (PTL 2) to Patent literature 4 (PTL 4) will be noted as below.
  • the present invention has been made in view of such circumstances, and the objective of the present invention is to provide a sound source position detection device and the like which are capable of detecting a position of a sound source accurately.
  • a sound source position detection device of the present invention includes:
  • a pair of signal measurement units disposed separately from each other and each configured to measure a signal output from a sound source as a measured signal
  • reference signal acquisition units each configured to acquire a reference signal
  • a weighting processing unit configured to create weighted reference signals by weighting the reference signals measured by the respective reference signal acquisition units
  • a time synchronization correction calculation unit configured to calculate a time synchronization correction value on the basis of the weighted reference signals, the time synchronization correction value being a correction value for synchronizing the two measured signals measured by respective ones of the pair of signal measurement units with each other;
  • an arrival time difference calculation unit configured to calculate an arrival time difference on the basis of the time synchronization correction value, the arrival time difference being a difference between elapsed times for the two measured signals measured by respective ones of the pair of signal measurement units to arrive at the respective ones of the pair of signal measurement units;
  • a sound source position calculation unit configured to calculate a position of the sound source on the basis of the arrival time difference.
  • a sound source position detection method of the present invention includes:
  • a time synchronization correction calculation step of calculating a time synchronization correction value on the basis of the weighted reference signals, the time synchronization correction value being a correction value for synchronizing the two measured signals measured by respective ones of the pair of signal measurement units with each other;
  • a sound source position calculation step of calculating a position of the sound source on the basis of the arrival time difference.
  • a sound source position detection program of the present invention causes a computer to execute a process including:
  • a time synchronization correction calculation step of calculating a time synchronization correction value on the basis of the weighted reference signals, the time synchronization correction value being a correction value for synchronizing the two measured signals measured by respective ones of the pair of signal measurement units with each other;
  • a sound source position calculation step of calculating a position of the sound source on the basis of the arrival time difference.
  • a recording medium of the present invention stores a sound source position detection program for causing a computer to execute a process including:
  • a time synchronization correction calculation step of calculating a time synchronization correction value on the basis of the weighted reference signals, the time synchronization correction value being a correction value for synchronizing the two measured signals measured by respective ones of the pair of signal measurement units with each other;
  • a sound source position calculation step of calculating a position of the sound source on the basis of the arrival time difference.
  • a position of a sound source can be detected with high accuracy.
  • FIG. 1 is a diagram showing a schematic configuration of a sound source position detection device in a first exemplary embodiment of the present invention.
  • FIG. 2 is a diagram showing a configuration of a measurement device.
  • FIG. 3 is a diagram showing a configuration of a position detection device.
  • FIG. 4 is a diagram showing an operational flow of the sound source position detection device in the first exemplary embodiment of the present invention.
  • FIGS. 5( a )-5( c ) are reference diagrams for explaining operation and effect of the sound source position detection device in the first exemplary embodiment of the present invention.
  • FIGS. 5( a ) and ( b ) are each an example of a raw waveform of a reference signal received by the measurement device.
  • FIG. 5( c ) is a diagram showing a correlation function between the raw reference signal waveforms respectively shown in FIGS. 5( a ) and ( b ) .
  • FIGS. 6( a )-6( c ) are reference diagrams for explaining operation and effect of the sound source position detection device in the first exemplary embodiment of the present invention.
  • FIGS. 6( a ) and ( b ) are each an example of a temporal waveform obtained by weighting a reference signal received by the measurement device.
  • FIG. 6( c ) is a diagram showing a correlation function between the temporal reference signal waveforms respectively shown in FIGS. 6( a ) and ( b ) .
  • FIGS. 7( a )-7( c ) are reference diagrams for explaining operation and effect of the sound source position detection device in the first exemplary embodiment of the present invention.
  • FIGS. 7( a ) and ( b ) are each an example of a temporal waveform obtained by weighting a reference signal received by the measurement device.
  • FIG. 7( c ) is a diagram showing a correlation function between the temporal reference signal waveforms respectively shown in FIGS. 7( a ) and ( b ) .
  • FIGS. 8( a )-8( c ) are reference diagrams for explaining operation and effect of the sound source position detection device in the first exemplary embodiment of the present invention.
  • FIGS. 8( a ) and ( b ) are each an example of a temporal waveform obtained by weighting a reference signal received by the measurement device.
  • FIG. 8( c ) is a diagram showing a correlation function between the temporal reference signal waveforms respectively shown in FIGS. 8( a ) and ( b ) .
  • FIG. 9 is a diagram showing an operational flow of a sound source position detection device in a second exemplary embodiment of the present invention.
  • FIG. 10 is a diagram for explaining a process step shown in FIG. 9 .
  • FIG. 11 is a diagram showing a schematic configuration of a sound source position detection device in a third exemplary embodiment of the present invention.
  • FIG. 12 is a diagram showing a configuration of a measurement device.
  • FIG. 13 is a diagram showing a configuration of a position detection device.
  • FIG. 14 is a diagram showing an operational flow of the sound source position detection device in the third exemplary embodiment of the present invention.
  • the sound source position detection device 100 includes two measurement devices 10 a and 10 b and a position detection device 20 .
  • the two measurement devices 10 a and 10 b are a pair of measurement devices.
  • the measurement device 10 a and the measurement device 10 b are disposed separately from each other. When there is no need of distinguishing between the two measurement devices 10 a and 10 b , they are collectively referred to as a measurement device 10 .
  • Each of the measurement devices 10 a and 10 b is communicatively coupled with the position detection device 20 by wired or wireless.
  • the measurement device 10 a receives a reference signal 1 a .
  • the measurement device 10 b receives a reference signal 1 b.
  • FIG. 2 is a diagram showing a configuration of the measurement device 10 ( 10 a , 10 b ).
  • Each of the measurement devices 10 a and 10 b has a configuration described below. That is, as shown in FIG. 2 , the measurement device 10 ( 10 a , 10 b ) includes a signal measurement unit 11 , a measured signal data storage unit 12 , a measured signal data transmission unit 13 , a reference signal acquisition unit 14 , a reference signal data storage unit 15 and a reference signal data transmission unit 16 .
  • the signal measurement unit 11 is coupled with the measured signal data storage unit 12 .
  • the signal measurement unit 11 measures a signal output from a sound source (not illustrated) as a measured signal, based on sound or vibration emitted from the sound source. That is, the signal measurement unit 11 detects sound or vibration emitted from a subject whose position is desired to be identified. Based on the detected sound or vibration, the signal measurement unit 11 measures a measured signal.
  • the measurement device 10 a and the measurement device 10 b are disposed separately from each other. Accordingly, the signal measurement unit 11 of the measurement device 10 a and the signal measurement unit 11 of the measurement device 10 b each measure a signal output from the sound source as a measured signal, at a different site from the other's site.
  • the signal measurement unit 11 outputs the measured signal to the measured signal data storage unit 12 .
  • the signal measurement unit 11 may perform the signal measurement either constantly or intermittently.
  • the measured signal data storage unit 12 is coupled to the signal measurement unit 11 and the measured signal data transmission unit 13 .
  • the measured signal data storage unit 12 stores the measured signal output from the signal measurement unit 11 .
  • the measured signal data transmission unit 13 is coupled to the measured signal data storage unit 12 .
  • the measured signal data transmission unit 13 is coupled also to a measured signal data reception unit 22 a or 22 b of the position detection device 20 , which will be described later. More specifically, the measured signal data transmission unit 13 of the measurement device 10 a is coupled to the measured signal data reception unit 22 a of the position detection device 20 .
  • the measured signal data transmission unit 13 of the measurement device 10 b is coupled to the measured signal data reception unit 22 b of the position detection device 20 .
  • the measured signal data transmission unit 13 transmits the measured signal stored in the measured signal data storage unit 12 to the position detection device 20 .
  • the reference signal acquisition unit 14 is coupled to the reference signal data storage unit 15 .
  • the reference signal acquisition unit 14 acquires a reference signal to be used for time synchronization. More specifically, for example, the reference signal acquisition unit 14 receives the reference signal via a radio wave of such as radio broadcast and GPS (Global Positioning System) signals.
  • the reference signal acquisition unit 14 of the measurement device 10 a acquires the reference signal 1 a .
  • the reference signal acquisition unit 14 of the measurement device 10 b acquires the reference signal 1 b .
  • the reference signal acquisition unit 14 outputs the acquired reference signal to the reference signal data storage unit 15 .
  • the reference signal acquisition unit 14 may receive a reference signal either constantly or intermittently.
  • the reference signal data storage unit 15 is coupled to the reference signal acquisition unit 14 and the reference signal data transmission unit 16 .
  • the reference signal data storage unit 15 stores a reference signal output from the reference signal acquisition unit 14 .
  • the reference signal data transmission unit 16 is coupled to the reference signal data storage unit 15 .
  • the reference signal data transmission unit 16 is coupled also to the reference signal data reception unit 21 a or 21 b of the position detection device 20 described later. More specifically, the reference signal data transmission unit 16 of the measurement device 10 a is coupled to the reference signal data reception unit 21 a of the position detection device 20 .
  • the reference signal data transmission unit 16 of the measurement device 10 b is coupled to the reference signal data reception unit 21 b of the position detection device 20 .
  • the reference signal data transmission unit 16 transmits a reference signal stored in the reference signal data storage unit 15 to the position detection device 20 .
  • FIG. 3 is a diagram showing the configuration of the position detection device 20 .
  • the position detection device 20 includes the reference signal data reception units 21 a and 21 b , the measured signal data reception unit 22 a and 22 b , a weighting processing unit 23 , a time synchronization correction calculation unit 24 , a measured data time correction unit 25 , an arrival time difference calculation unit 26 , a sound velocity storage unit 27 , a distance storage unit 28 and a sound source position calculation unit 29 .
  • the weighting processing unit 23 is coupled to the reference signal data reception units 21 a and 21 b and the time synchronization correction calculation unit 24 .
  • the weighting processing unit 23 weights each of the reference signals measured by the reference signal acquisition units 14 of respective ones of the measurement devices 10 a and 10 b , thereby generating weighted reference signals.
  • the weighting is performed partitioning each of the reference signals at a constant interval of time.
  • the weighting processing unit 23 outputs the weighted reference signals to the time synchronization correction calculation unit 24 .
  • the time synchronization correction calculation unit 24 is coupled to the weighting processing unit 23 and the measured data time correction unit 25 .
  • the time synchronization correction calculation unit 24 calculates a time synchronization correction value on the basis of the weighted reference signals.
  • the time synchronization correction value is a correction value for synchronizing the two measured signals measured by respective ones of the pair of signal measurement units 11 (the signal measurement unit 11 of the measurement device 10 a and the signal measurement unit 11 of the measurement device 10 b ) with each other.
  • the time synchronization correction calculation unit 24 outputs the time synchronization correction value to the measured data time correction unit 25 .
  • the measured data time correction unit 25 is coupled to the measured signal data reception units 22 a and 22 b , the time synchronization correction calculation unit 24 and the arrival time difference calculation unit 26 . Based on the time synchronization correction value, the measured data time correction unit 25 performs time synchronization correction on the measured signals, thereby creating time synchronization corrected measured signals. The measured data time correction unit 25 outputs the time synchronization corrected measured signals to the arrival time difference calculation unit 26 .
  • the arrival time difference calculation unit 26 is coupled to the measured data time correction unit 25 and the sound source position calculation unit 29 .
  • the arrival time difference calculation unit 26 calculates an arrival time difference, using the time synchronization corrected measured signals.
  • the arrival time difference is a difference between elapsed times for the two measured signals acquired by respective ones of the pair of signal measurement units (the signal measurement unit 11 of the measurement device 10 a and the signal measurement unit 11 of the measurement device 10 b ) to arrive at the respective ones of the pair of signal measurement units 11 .
  • the time synchronization corrected measured signals have been created on the basis of the time synchronization correction value, as described earlier.
  • the arrival time difference calculation unit 26 calculates the arrival time difference on the basis of the time synchronization correction value.
  • a correlation function is used for the calculation of the arrival time difference.
  • the arrival time difference calculation unit 26 outputs the calculated arrival time difference to the sound source position calculation unit 29 .
  • the distance storage unit 28 is coupled to the sound source position calculation unit 29 .
  • a distance between the pair of measurement devices 10 a and 10 b is stored. More specifically, in the distance storage unit 28 , a distance between the pair of signal measurement units 11 (the signal measurement unit 11 of the measurement device 10 a and the signal measurement unit 11 of the measurement device 10 b ) is stored.
  • a distance between the measurement device 10 a (more specifically, the signal measurement unit 11 of the measurement device 10 a ) and the sound source is denoted by L 1 .
  • a distance between the measurement device 10 b (more specifically, the signal measurement unit 11 of the measurement device 10 b ) and the sound source is denoted by L 2 .
  • the sound velocity is denoted by c, and the arrival time difference by ⁇ .
  • L 1 ( L 2 ⁇ c ⁇ )/2 (equation 1)
  • the sound source position calculation unit 29 can calculate the distance L 1 between the measurement device 10 a (more specifically, the signal measurement unit 11 of the measurement device 10 a ) and the sound source. As a result, the sound source position detection device 100 can detect a position of the sound source.
  • the configuration of the sound source position detection device 100 has been described above.
  • FIG. 4 is a diagram showing an operational flow of the sound source position detection device 100 .
  • the measurement devices 10 a and 10 b each acquire a reference signal and a measured signal (S 1 ).
  • the position detection device 20 acquires data on the reference signals and the measured signals from the measurement devices 10 a and 10 b (S 2 ).
  • the measured signal data reception unit 22 a receives the measured signal transmitted from the measured signal data transmission unit 13 of the measurement device 10 a .
  • the measured signal data reception unit 22 b receives the measured signal transmitted from the measured signal data transmission unit 13 of the measurement device 10 b.
  • the position detection device 20 weights the reference signals at a constant interval of time (S 3 ).
  • the weighting processing unit 23 creates weighted reference signals by weighting each of the reference signals measured by the reference signal acquisition units 14 of respective ones of the measurement devices 10 a and 10 b , at a constant interval of time.
  • the weighting processing unit 23 outputs the weighted reference signals to the time synchronization correction calculation unit 24 .
  • the time synchronization correction calculation unit 24 calculates the time synchronization correction value, based on the weighted reference signals.
  • the time synchronization correction value is, as described earlier, a correction value for synchronizing the two measured signals measured by respective ones of the pair of signal measurement units 11 (the signal measurement unit 11 of the measurement device 10 a and the signal measurement unit 11 of the measurement device 10 b ) with each other.
  • the time synchronization correction calculation unit 24 outputs the time synchronization correction value to the measured data time correction unit 25 .
  • the position detection device 20 performs a time synchronization correction process on data on the measured signals (S 5 ).
  • the measured data time correction unit 25 creates time synchronization corrected measured signals by performing time synchronization correction on the measured signals on the basis of the time synchronization correction value.
  • the measured data time correction unit 25 outputs the time synchronization corrected measured signals to the arrival time difference calculation unit 26 .
  • the position detection device 20 calculates a position of the sound source (S 7 ).
  • the sound velocity c, the distances L 1 and L 2 , and the arrival time difference ⁇ are defined as described earlier. Accordingly, by using the equation 1, the sound source position calculation unit 29 of the position detection device 20 can calculate the distance L 1 between the measurement device 10 a (more specifically, the signal measurement unit 11 of the measurement device 10 a ) and the sound source. As a result, the sound source position detection device 100 can detect a position of the sound source.
  • the pair of signal measurement units 11 are disposed separately from each other, and each measure a signal output from a sound source as a measured signal.
  • the reference signal acquisition units 14 each acquire a reference signal.
  • the weighting processing unit 23 creates weighted reference signals by weighting the reference signals measured by the reference signal acquisition units 14 .
  • the time synchronization correction calculation unit 24 calculates a time synchronization correction value, based on the weighted reference signals.
  • the time synchronization correction value is a correction value for synchronizing the two measured signals measured by respective ones of the pair of signal measurement units 11 .
  • the arrival time difference calculation unit 26 calculates an arrival time difference, based on the time synchronization correction value.
  • the weighting processing unit 23 creates the weighted reference signals by weighting the reference signals measured by the reference signal acquisition units 14 .
  • the time synchronization correction calculation unit 24 calculates the time synchronization correction value, based on the weighted reference signals. In that way, it becomes possible to calculate the time synchronization correction value more exactly, compared with a case of not weighting the reference signals.
  • the arrival time difference calculation unit 26 calculates the arrival time difference, based on the more exact time synchronization correction value. Accordingly, it becomes possible to calculate the arrival time difference more exactly, compared with a case of not weighting the reference signals.
  • the sound source position calculation unit 29 calculates a position of the sound source, based on the more exact arrival time difference. Accordingly, it becomes possible to calculate the position of the sound source more exactly, compared with a case of not weighting the reference signals.
  • the sound source position detection device 100 As a result, by using the sound source position detection device 100 according to the present invention, it becomes possible to detect a position of a sound source with high accuracy.
  • a case considered here is that where a sampling frequency is the same for timers (not illustrated) provided respectively in the measurement device 10 a and the measurement device 10 b and a value whose correction is necessary in terms of time synchronization is only a measurement start time difference.
  • FIGS. 5( a )-5( c ) are reference diagrams for explaining the operation and effect of the sound source position detection device 100 .
  • FIG. 5( a ) is an example of a raw waveform of a reference signal received by the measurement device 10 a .
  • FIG. 5( b ) is an example of a raw waveform of a reference signal received by the measurement device 10 b .
  • FIG. 5( c ) is a diagram showing a correlation function between the raw reference signal waveform shown in FIG. 5( a ) and the raw reference signal waveform shown in FIG. 5( b ) .
  • the cross-correlation function should have a maximum value at one second, corresponding to the difference between the measurement start times, in an ideal condition having no noise.
  • the cross-correlation function when noise is present, if a cross-correlation function is calculated without weighting the reference signals received by the measurement device 10 a and the measurement device 10 b , the cross-correlation function has a maximum value at a time difference not equal to one second, as shown in FIG. 5( a ) . Accordingly, if not weighting the reference signals, the measured data time correction unit 25 cannot perform time synchronization correction exactly.
  • a noise magnitude is estimated from silent sections, and multiplication by the square of a value obtained by subtracting the noise magnitude, which is taken as a weight, is performed at a constant interval of time.
  • FIGS. 7( a )-7( c ) are reference diagrams for explaining the operation and effect of the sound source position detection device 100 .
  • FIG. 7( a ) is an example of a temporal waveform obtained by weighting a reference signal received by the measurement device 10 a .
  • FIG. 7( b ) is an example of a temporal waveform obtained by weighting a reference signal received by the measurement device 10 b .
  • FIG. 7( c ) is a diagram showing a correlation function between the temporal reference signal waveform shown in FIG. 7( a ) and the temporal reference signal waveform shown in FIG. 7( b ) .
  • the cross-correlation function has a maximum value at one second, corresponding to the difference between the measurement start times, in an ideal condition having no noise.
  • the measurement start time difference is calculated using a maximum value of the cross-correlation function
  • the reference signals are periodic signals
  • a difference between a maximum value of the cross-correlation function and the next largest value becomes small and, accordingly, it is possible that the measurement start time difference is calculated incorrectly.
  • the correlation function has a maximum value at a time difference not equal to one second and, accordingly, time synchronization correction cannot be performed exactly.
  • FIGS. 8( a )-8( c ) are reference diagrams for explaining the operation and effect of the sound source position detection device 100 .
  • FIG. 8( a ) is an example of a temporal waveform obtained by weighting the reference signal received by the measurement device 10 a .
  • FIG. 8( b ) is an example of a temporal waveform obtained by weighting the reference signal received by the measurement device 10 b .
  • FIG. 8( c ) is a diagram showing a correlation function between the temporal reference signal waveform shown in FIG. 8( a ) and the temporal reference signal waveform shown in FIG. 8( b ) .
  • the cross-correlation function between these weighted reference signals has a maximum value at one second, which indicates that the measurement start time difference can be calculated correctly. That is, according to the sound source position calculation device 100 of the present exemplary embodiment, the measurement start time difference can be calculated exactly, by performing the weighting process on received reference signals. As a result, by performing time synchronization correction between the measurement device 10 a and the measurement device 10 b using the exact measurement start time difference, the accuracy of calculating a sound source position can be improved.
  • weighting has an effect on the accuracy of time synchronization.
  • weighting has an effect on a filtering process and averaging. Accordingly, there is difference in operation and effect. Specifically, in the technology disclosed in PTL 1, smoothing is performed by a filtering process, but high frequency components of a reference signal are removed when the smoothing is performed and, accordingly, the accuracy of time synchronization deteriorates. In contrast, in the invention in the present exemplary embodiment, weighting is performed instead of smoothing and, accordingly, the high frequency components can be maintained, which enables accurate time synchronization.
  • the weighting processing unit 23 may create two weighted reference signals by weighting each of two reference signals acquired by the pair of reference signal acquisition units 14 on the basis of the reference signal's signal to noise ratio. In that way, weighted reference signals can be easily created.
  • the time synchronization correction value is a correction value for a measurement start time difference which is a difference between the pair of signal measurement units 11 in time to start measuring a measured signal. Accordingly, based on the correction value for the measurement start time difference, an arrival time difference can be calculated.
  • the reference signals are radio broadcast signals. Accordingly, reference signals keeping precise time can be easily acquired.
  • a sound source position detection method in the first exemplary embodiment of the present invention includes a signal measurement step, a reference signal acquisition step, a weighting processing step, a time synchronization correction calculation step, an arrival time difference calculation step and a sound source position calculation step.
  • a signal output from a sound source is measured as a measured signal by each of the pair of signal measurement units 11 which are disposed separately from each other.
  • a reference signal is acquired by each of the reference signal acquisition units 14 .
  • weighted reference signals are created by weighting the reference signals acquired by the reference signal acquisition units 14 .
  • time synchronization correction calculation step a time synchronization correction value is calculated on the basis of the weighted reference signals.
  • the time synchronization correction value is a correction value for synchronizing the two measured signals measured by respective ones of the pair of signal measurement units with each other.
  • an arrival time difference is calculated on the basis of the time synchronization correction value.
  • the arrival time difference is a difference between elapsed times for the two measured signals measured by respective ones of the pair of signal measurement units 11 to arrive at the respective ones of the pair of signal measurement units 11 .
  • a position of the sound source is calculated on the basis of the arrival time difference.
  • the above-described effect achieved by the sound source position detection device 100 can be achieved.
  • a sound source position detection program in the first exemplary embodiment of the present invention causes a computer to execute a process including the above-mentioned signal measurement step, reference signal acquisition step, weighting processing step, time synchronization correction calculation step, arrival time difference calculation step and sound source position calculation step.
  • the above-described effect achieved by the sound source position detection device 100 can be achieved.
  • a recording medium in the first exemplary embodiment of the present invention stores a sound source position detection program for causing a computer to execute a process including the above-mentioned signal measurement step, reference signal acquisition step, weighting processing step, time synchronization correction calculation step, arrival time difference calculation step and sound source position calculation step.
  • the above-described effect achieved by the sound source position detection device 100 can be achieved.
  • the sound source position detection device in the second exemplary embodiment of the present invention has basically the same configuration as that of the sound source position detection device 100 in the first exemplary embodiment (refer to FIGS. 1 to 3 ). Accordingly, a diagram showing the configuration of the sound source position detection device in the second exemplary embodiment will be omitted.
  • the sound source position calculation device in the present exemplary embodiment is different from the sound source position calculation device 100 in the first exemplary embodiment in that not only the measurement start time difference between the measurement devices 10 a , 10 b but also the sampling frequency difference is corrected. Accordingly, in the following description of the sound source position calculation device of the present exemplary embodiment, any description overlapping with that in the first exemplary embodiment will be omitted.
  • the time synchronization correction value calculation unit 24 changes a sampling frequency of the weighted reference signals by interpolation (S 8 ).
  • the time synchronization correction value calculation unit 24 determines a plurality of sampling frequencies to investigate (hereafter assumed to be sampling frequencies f1, f2, . . . , fN).
  • the plurality of sampling frequencies to investigate those obtained by equally dividing a variability range, according to specifications, of the sampling frequency of timers installed in the measurement devices 10 a and 10 b by a required accuracy of the sampling frequency can be considered.
  • the time synchronization correction value calculation unit 24 calculates a weighted reference signal for the measurement device 10 a by interpolation such that the sampling frequency be equal to f1.
  • the time synchronization correction value calculation unit 24 calculates a peak value of a cross-correlation function between a reference signal with a changed sampling frequency and a weighted reference signal (S 9 ). Specifically, the time synchronization correction value calculation unit 24 calculates a peak value of a cross-correlation function between an interpolated reference signal for the measurement device 10 a and a weighted reference signal for the measurement device 10 b.
  • the time synchronization correction value calculation unit 24 determines whether or not the investigation has been completed over a sampling frequency range planned to be investigated (S 10 ). Specifically, the time synchronization correction value calculation unit 24 determines whether the currently investigated sampling frequency is fN. If the currently investigated sampling frequency is fN (Yes at S 10 ), a sampling frequency fcomp for which a peak value of the cross-correlation function becomes largest is extracted (S 11 ). A time difference giving a peak value of the cross-correlation function between an interpolated reference signal for the measurement device 10 a at the extracted sampling frequency and the weighted reference signal for the measurement device 10 b is determined to be a measurement start time difference. By performing correction of measured signal data by taking the above-mentioned sampling frequency fcomp and measurement start time difference as time synchronization correction values, highly accurate time synchronization becomes possible.
  • FIG. 10 is a diagram for explaining the process steps shown in FIG. 9 .
  • a sampling frequency correction parameter is set as the horizontal axis
  • a coincidence degree between reference signals (a peak value of the cross-correlation function) is set as the vertical axis.
  • the sampling frequency correction parameter represented by the horizontal axis is that obtained by normalizing an investigated sampling frequency by the original sampling frequency.
  • the coincidence degree between reference signals (a peak value of the cross-correlation function) represented by the vertical axis is a peak value of the cross-correlation function between an interpolated reference signal for the measurement device 10 a and the weighted reference signal for the measurement device 10 b.
  • a largest one of peak values of the cross-correlation function between an interpolated reference signal for the measurement device 10 a and the weighted reference signal for the measurement device 10 b is determined as the sampling frequency fcomp.
  • time synchronization correction values include a correction value for the measurement start time difference and a correction value for a given sampling frequency difference included in measured signals.
  • correction is performed not only on the measurement start time difference between the measurement devices 10 a and 10 b but also on the sampling frequency difference, and as a result, highly accurate calculation of a sound source position is possible even using measurement devices provided with low cost timers having a large individual difference in sampling frequency.
  • the fact that such low cost timers can be used becomes important in applications using a large number of measurement devices, such as a sensor network.
  • FIG. 11 is a diagram showing a schematic configuration of the sound source position detection device 200 in the third exemplary embodiment of the present invention.
  • FIG. 11 to constituent elements equivalent to the respective constituent elements shown in FIGS. 1 to 10 , equivalent signs to those shown in FIGS. 1 to 10 are assigned.
  • the sound source position calculation device 200 in the present exemplary embodiment is different from the sound source position detection device 100 in the first exemplary embodiment in that it uses a plurality of reference signals. Accordingly, in the following description of the sound source position calculation device of the present exemplary embodiment, any description overlapping with that in the first exemplary embodiment will be omitted.
  • the sound source position detection device 200 includes two measurement devices 30 a and 30 b and a position detection device 40 .
  • the two measurement devices 30 a and 30 b are a pair of measurement devices.
  • a measurement device 30 When there is no need of distinguishing between the two measurement devices 30 a and 30 b , they are collectively referred to as a measurement device 30 .
  • Each of the measurement device 30 a and the measurement device 30 b is communicatively coupled with the position detection device 40 by wired or wireless.
  • the measurement device 30 a receives reference signals 1 a and 2 a .
  • the measurement device 30 b receives reference signals 1 b and 2 b .
  • each of the measurement devices 10 a and 10 b uses two reference signals.
  • each of the measurement devices 10 a and 10 b may use three or more reference signals.
  • FIG. 12 is a diagram showing a configuration of the measurement device 30 ( 30 a , 30 b ).
  • the position detection device 30 ( 30 a , 30 b ) includes a signal measurement unit 11 , a measured signal data storage unit 12 , a measured signal data transmission unit 13 , reference signal acquisition units 14 a and 14 b , a reference signal data storage unit 15 and a reference signal data transmission unit 16 .
  • FIG. 2 the single reference signal acquisition unit 14 is provided in the measurement device 10 .
  • the two reference signal acquisition units 14 a and 14 b are provided in the measurement device 30 .
  • the reference signal acquisition units 14 a and 14 b are coupled to the reference signal data storage unit 15 .
  • the reference signal acquisition units 14 a and 14 b each have basically the same function as that of the reference signal acquisition unit 14 of FIG. 2
  • the reference signal acquisition units 14 a and 14 b each receive a reference signal through a radio wave of such as radio broadcast and GPS signals.
  • the reference signal acquisition units 14 a and 14 b each output the acquired reference signal to the reference signal data storage unit 15 .
  • the reference signal acquisition units 14 a and 14 b may receive reference signals simultaneously with each other and store the reference signals, in a manner to combine them together, into the reference signal data storage unit 15 .
  • the reference signal acquisition units 14 a and 14 b may also periodically switch a reference signal to receive and store thus received reference signals into the reference signal data storage unit 15 .
  • the reference signal acquisition units 14 a and 14 b may store, into the reference signal data storage unit 15 , a reference signal having a best signal to noise ratio at each of placement sites of the respective measurement devices 30 a and 30 b .
  • a reference signal having a best signal to noise ratio at each of placement sites of the respective measurement devices 30 a and 30 b it may occur that the used reference signal is different between the plurality of measurement devices 30 a and 30 b . Because of the reason, all of the reference signals may be recorded by another recording device different from the reference signal data storage unit 15 . Accordingly, by taking the reference signals recorded in the another recording device as master reference signal data and comparing the data with reference signals of the respective measurement devices 30 a and 30 b , time synchronization can be performed.
  • FIG. 13 is a diagram showing the configuration of the position detection device 40 .
  • the position detection device 40 includes reference signal data reception units 21 a and 21 b , measured signal data reception units 22 a and 22 b , a reference signal separation unit 41 , a weighting processing unit 23 , a time synchronization correction calculation unit 24 , a measured data time correction unit 25 , an arrival time difference calculation unit 26 , a sound velocity storage unit 27 , a distance storage unit 28 and a sound source position calculation unit 29 .
  • FIG. 13 is different from FIG. 3 in that the reference signal separation unit 41 is further provided.
  • the reference signal separation unit 41 is coupled to the reference signal data reception units 21 a and 21 b and the weighting processing unit 23 .
  • the reference signal separation unit 41 separates reference signals received by the reference signal data reception units 21 a and 21 b .
  • the reference signal separation unit 41 separates reference signals received by the reference signal data reception units 21 a and 21 b into individual reference signals acquired by the respective reference signal acquisition units 14 a and 14 b .
  • the weighting processing unit 23 weights each of the reference signals separated by the reference signal separation unit 41 , thereby creating weighted reference signals.
  • the time synchronization correction value calculation unit 24 calculates a time synchronization correction value in terms of each of the plurality of weighted reference signals.
  • the measured data time correction unit 25 may perform time synchronization of measured signal data using an average of the time correction value calculated in terms of each of the reference signals, and accordingly create time synchronization corrected measured signals.
  • the configuration of the sound source position detection device 200 has been described above.
  • FIG. 14 is a diagram showing an operational flow of the sound source position detection device 200 .
  • FIG. 14 is different from FIG. 4 in that S 12 is added.
  • S 12 is added.
  • a description will be given mainly of a different point from the description of FIG. 4 , and any content overlapping with the description of FIG. 4 will be omitted.
  • the position detection device 40 separates reference signals after the process of S 2 (S 12 ).
  • the reference signal separation unit 41 separates reference signals received by the reference signal data reception units 21 a and 21 b into individual signals.
  • the reference signal data storage unit 15 stores also information on time at which a reference signal is changed, at the same time when data on the reference signal is stored. Based on the information, the reference signal separation unit 410 can separate reference signals.
  • the reference signal separation unit 41 can separate reference signals by signal processing.
  • the position detection device 20 weights reference signals at a constant interval of time (S 3 ).
  • the weighting processing unit 23 creates weighted reference signals by weighting the reference signals separated by the reference signal separation unit 41 at a constant interval of time.
  • the weighting processing unit 23 outputs the weighted reference signals to the time synchronization correction calculation unit 24 .
  • Steps after S 4 are the same as that described in the first exemplary embodiment.
  • the pair of reference signal acquisition units 14 each acquire a plurality of kinds of reference signals different from each other.
  • the weighting processing unit 23 creates weighted reference signals by weighting each of the plurality of kinds of reference signals acquired by each of the reference signal acquisition units 14 .
  • the device of each of the exemplary embodiments is realized by any combination of hardware and software including mainly any computer CPU, memory, program loaded on the memory, storage unit storing the program such as a hard disk, and interface for network connection.
  • the above-mentioned program includes, besides a program already stored in the memory since a stage of shipping the device, also a program downloaded from a recording medium such as a CD, a server on the Internet or the like.
  • a recording medium such as a CD, a server on the Internet or the like.
  • the functional block diagrams used in describing the exemplary embodiments each show a configuration not in terms of hardware units but in terms of functional units. While, in those diagrams, each device is illustrated as being realized by a single apparatus, the realization means is not limited to that. That is, either a physically divided configuration or a logically divided one may be employed.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)
  • Length Measuring Devices Characterised By Use Of Acoustic Means (AREA)
  • Examining Or Testing Airtightness (AREA)
US15/577,569 2015-06-23 2016-06-17 Sound source position detection device, sound source position detection method, sound source position detection program, and recording medium Active 2037-06-30 US10845460B2 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2015-125700 2015-06-23
JP2015125700 2015-06-23
PCT/JP2016/002925 WO2016208167A1 (fr) 2015-06-23 2016-06-17 Dispositif de détection de position de source sonore, procédé de détection de position de source sonore, programme de détection de position de source sonore, et support d'enregistrement

Publications (2)

Publication Number Publication Date
US20180164403A1 US20180164403A1 (en) 2018-06-14
US10845460B2 true US10845460B2 (en) 2020-11-24

Family

ID=57586169

Family Applications (1)

Application Number Title Priority Date Filing Date
US15/577,569 Active 2037-06-30 US10845460B2 (en) 2015-06-23 2016-06-17 Sound source position detection device, sound source position detection method, sound source position detection program, and recording medium

Country Status (4)

Country Link
US (1) US10845460B2 (fr)
JP (1) JP6741004B2 (fr)
GB (1) GB2555278B (fr)
WO (1) WO2016208167A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20210185690A1 (en) * 2018-08-14 2021-06-17 Huawei Technologies Co., Ltd. Resource management method and apparatus

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017138043A1 (fr) * 2016-02-12 2017-08-17 Sony Mobile Communications Inc. Positionnement d'objets basé sur la télémétrie acoustique, utilisant des enregistrements sonores par des terminaux
IT201700035316A1 (it) * 2017-03-30 2018-09-30 Telecom Italia Spa Metodo e sistema di cooperazione tra access gateway per la condivisione di banda
JP6840066B2 (ja) * 2017-11-22 2021-03-10 株式会社日立製作所 漏水検知システムおよび漏水検知方法
US20200333429A1 (en) * 2017-12-29 2020-10-22 Ubicquia Iq Llc Sonic pole position triangulation in a lighting system
KR20210095284A (ko) * 2020-01-22 2021-08-02 삼성전자주식회사 사용자의 위치를 결정하는 시스템 및 방법
CN111983357B (zh) * 2020-08-21 2022-08-09 国网重庆市电力公司电力科学研究院 一种结合声纹检测功能的超声可视化故障检测方法
CN113197551B (zh) * 2021-05-07 2023-08-04 中国医学科学院生物医学工程研究所 多模生理神经信号检测与实验刺激时间对齐方法
CN115426067A (zh) * 2022-09-01 2022-12-02 安徽聆思智能科技有限公司 一种音频信号同步方法和相关装置

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08226865A (ja) 1994-11-09 1996-09-03 At & T Corp 導管の漏れの位置を決定する方法
JPH1090106A (ja) 1996-09-19 1998-04-10 Fuji Tecomu Kk 漏洩探査装置
JP2002071784A (ja) 2000-08-30 2002-03-12 Tech Res & Dev Inst Of Japan Def Agency 航走体放射雑音からの航跡標定方法及び装置
JP2002162195A (ja) 2000-11-21 2002-06-07 Toshiba Corp 飛翔体誘導装置
US20060241914A1 (en) * 2000-01-06 2006-10-26 Barnard Thomas J Subarray matching beamformer apparatus and method
JP2011504597A (ja) 2007-11-25 2011-02-10 スカイ タッガー エル・エル・シー 航行データ収集および信号の後処理
JP2012169993A (ja) 2011-02-16 2012-09-06 Nippon Telegr & Teleph Corp <Ntt> コンテンツ同期装置、コンテンツ同期方法及びコンテンツ同期プログラム
JP2012242542A (ja) 2011-05-18 2012-12-10 Nippon Hoso Kyokai <Nhk> 音声比較装置及び音声比較プログラム
JP2014232267A (ja) 2013-05-30 2014-12-11 株式会社ニコン 信号処理装置、撮像装置、およびプログラム
US9069065B1 (en) * 2012-06-27 2015-06-30 Rawles Llc Audio source localization

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08226865A (ja) 1994-11-09 1996-09-03 At & T Corp 導管の漏れの位置を決定する方法
JPH1090106A (ja) 1996-09-19 1998-04-10 Fuji Tecomu Kk 漏洩探査装置
US20060241914A1 (en) * 2000-01-06 2006-10-26 Barnard Thomas J Subarray matching beamformer apparatus and method
JP2002071784A (ja) 2000-08-30 2002-03-12 Tech Res & Dev Inst Of Japan Def Agency 航走体放射雑音からの航跡標定方法及び装置
JP2002162195A (ja) 2000-11-21 2002-06-07 Toshiba Corp 飛翔体誘導装置
JP2011504597A (ja) 2007-11-25 2011-02-10 スカイ タッガー エル・エル・シー 航行データ収集および信号の後処理
JP2012169993A (ja) 2011-02-16 2012-09-06 Nippon Telegr & Teleph Corp <Ntt> コンテンツ同期装置、コンテンツ同期方法及びコンテンツ同期プログラム
JP2012242542A (ja) 2011-05-18 2012-12-10 Nippon Hoso Kyokai <Nhk> 音声比較装置及び音声比較プログラム
US9069065B1 (en) * 2012-06-27 2015-06-30 Rawles Llc Audio source localization
JP2014232267A (ja) 2013-05-30 2014-12-11 株式会社ニコン 信号処理装置、撮像装置、およびプログラム

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
International Search Report for PCT/JP2016/002925, dated Aug. 30, 2016.
Osamu Hoshuyama, "Sampling Synchronization Using Radio Broadcast Signals for Distributed Microphone Arrays", IEICE Technical Report, Feb. 23, 2015, pp. 313-316, vol. 114, No. 473.
Written Opinion for PCT/JP2016/002925, dated Aug. 30, 2016 English translation.

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20210185690A1 (en) * 2018-08-14 2021-06-17 Huawei Technologies Co., Ltd. Resource management method and apparatus
US11963205B2 (en) * 2018-08-14 2024-04-16 Huawei Technologies Co., Ltd. Resource management method and apparatus

Also Published As

Publication number Publication date
GB2555278A (en) 2018-04-25
US20180164403A1 (en) 2018-06-14
GB2555278B (en) 2021-07-07
GB201719210D0 (en) 2018-01-03
JP6741004B2 (ja) 2020-08-19
WO2016208167A1 (fr) 2016-12-29
JPWO2016208167A1 (ja) 2018-04-05

Similar Documents

Publication Publication Date Title
US10845460B2 (en) Sound source position detection device, sound source position detection method, sound source position detection program, and recording medium
EP3043190A1 (fr) Système pour déterminer des informations de localisation
CN106154222B (zh) 一种利用无线电射频信号检测人的行走方向的方法
JP6526373B2 (ja) 局所的電波伝搬モデルを使用した測位
US9909949B2 (en) Leakage determination method, leakage determination system, and program
JP6626394B2 (ja) 漏水調査方法
KR102036649B1 (ko) 누수관리 시스템 및 이를 이용한 누수위치 예측 방법
JP2010230467A (ja) 測位システム、測位装置、測位方法、およびプログラム
WO2013093468A3 (fr) Procédé de contrôle de qualité d&#39;inversion de forme d&#39;onde totale
MX2016007402A (es) Sistema y metodo para medir onda de pulso de sujeto.
US20160061931A1 (en) Estimation system and reception node
EA201590605A1 (ru) Способ и кинематическая калибровочная система для измерения смещений и вибраций объектов и конструкций
JP6835352B2 (ja) 時刻補正装置、センサ装置、センサシステム、時刻補正方法及びプログラム
WO2013063193A3 (fr) Détermination de profil de dérive d&#39;horloge dans des récepteurs de système de navigation
JP6455873B2 (ja) 振動測定方法及び振動検出装置及び振動測定プログラム
KR20140118242A (ko) 초음파 신호의 위상천이 검출에 의한 정밀 거리측정방법
US9961511B2 (en) Position detection system, method therefor, and computer-readable medium
CN107534842A (zh) 通过位置已知的同步接收器来确定位置未知的发送器的位置的方法
US9791537B2 (en) Time delay estimation apparatus and time delay estimation method therefor
KR101086707B1 (ko) 주파수 발진기의 주파수 안정도 측정 장치 및 그를 이용한 주파수 안정도 측정 방법
JP2017096651A (ja) 時刻同期方法、振動センサー、振動検知装置、プログラム及び記録媒体
JP2016159128A (ja) 走者のスタートの動きを自動検知する無線式短距離走タイム計測システム．
JP2018059887A (ja) 空間距離算出装置
KR101508522B1 (ko) 동기 오차 산출 장치 및 방법
JP6349861B2 (ja) 漏洩検知装置、漏洩検知システム、漏洩検知方法及びプログラム

Legal Events

Date Code Title Description
AS Assignment

Owner name: NEC CORPORATION, JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:INOUE, HIROFUMI;SUZUKI, NAOFUMI;MATAGA, JUNICHIRO;REEL/FRAME:044237/0988

Effective date: 20171113

FEPP Fee payment procedure

Free format text: ENTITY STATUS SET TO UNDISCOUNTED (ORIGINAL EVENT CODE: BIG.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

STPP Information on status: patent application and granting procedure in general

Free format text: DOCKETED NEW CASE - READY FOR EXAMINATION

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: FINAL REJECTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: RESPONSE AFTER FINAL ACTION FORWARDED TO EXAMINER

STPP Information on status: patent application and granting procedure in general

Free format text: PUBLICATIONS -- ISSUE FEE PAYMENT VERIFIED

STCF Information on status: patent grant

Free format text: PATENTED CASE

MAFP Maintenance fee payment

Free format text: PAYMENT OF MAINTENANCE FEE, 4TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1551); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Year of fee payment: 4